FIX: Year.php getDefaultOptions now fixed, sets key as year. Also added YearTest unit test.

The default scaffolding for the Year type was failing, as getDefaultOptions was returning the following:

[0] => 2013
[1] => 2012
[2] => 2011
...

When it should have been returning:

[2013] => 2013
[2012] => 2012
[2011] => 2011

This merge fixes that, and adds a unit test as well.